Electrochromic materials have been one of focuses in material science researches in recent years. Compared to inorganic or organic small molecule electrochromic materials, polymer electrochromic materials have advantages of better coloring efficiency; fast electrochromic response; good chemical stability; easy preparation; longer cycle life; color-memory function; and adjustable color shade, Bayer company in German firstly synthesized a derivative of polythiophene, poly(ethylenedioxythiophene) (PEDOT), which is a thiophene electrochromic polymer whose color can change between blue and transparent. After that, a series of blue polythiophene electrochromic polymers has been developed. However, existing blue polythiophene electrochromic materials generally have poor transmittance, and no method for preparing blue polythiophene electrochromic materials on a large scale has been developed, which limits the spreading and application of such materials.
The present invention aims to provide a novel blue thiophene electrochromic compound having high transmittance and preparation method thereof.